百香果皮分级萃取物中多酚轮廓分析及其抗氧化活性物质筛选

么亚妹; 陈奕彤; 田永涛; 刘天悦; 王文蜀

doi:10.13386/j.issn1002-0306.2023070099

百香果皮分级萃取物中多酚轮廓分析及其抗氧化活性物质筛选

Analysis of Polyphenol Profiles in Fractional Extracts of Passion Fruit Peels and Screening of Their Antioxidant Active Substances

摘要

摘要: 为探究不同溶剂对百香果皮多酚的萃取效率，寻找其中抗氧化活性贡献大的特征多酚。选用石油醚、乙酸乙酯和正丁醇分级萃取百香果皮乙醇粗提物，采用分光光度法分别测定其总酚总黄酮含量，借助超高效液相色谱串联质谱解析各分级萃取物中酚类化合物，并结合非靶向代谢组学技术筛选差异代谢物并定量。选用DPPH自由基清除、ABTS⁺自由基清除和Fe²⁺还原法分析各分级萃取物体外抗氧化活性差异，通过皮尔逊相关性分析探寻百香果皮中抗氧化活性酚类标志物。结果表明：各萃取物总酚和总黄酮含量差异显著（P<0.05），由大到小依次为乙酸乙酯部位（EE）>正丁醇部位（BE）>乙醇粗提物（CE）>水部位（WE）>石油醚部位（PE）。从CE和各分级萃取物中共鉴定出33个酚类化合物，CE、EE和BE酚类化合物种类和数量较多。主成分分析（PCA）区分了各萃取物的代谢物，正交偏最小二乘法判别分析（OPLS-DA）对羟基苯甲酸、原儿茶酸、异槲皮苷和异荭草苷为差异物。EE中对羟基苯甲酸（653.44 μg/g）、异槲皮苷（2420.64 μg/g）和异荭草苷（113.23 μg/g）含量最高，CE中原儿茶酸（152.40 μg/g）含量最高。百香果皮各分级萃取物体外抗氧化活性差异显著，EE体外抗氧化能力最强，是优质的抗氧化剂开发部位。相关性分析结果显示，总酚和总黄酮是百香果皮抗氧化活性物质基础，异荭草苷和异槲皮苷是其中的抗氧化活性酚类标志物。研究结果为建立百香果皮相关抗氧化产品质量控制标准及精准开发利用百香果皮酚类化合物资源提供了基础数据。

Abstract: To investigate the extraction efficiency of polyphenols from passion fruit (Passiflora edulis Sims) peel by using different solvents and to identify the characteristic polyphenols with high contribution to antioxidant activity, ethanolic crude extract (CE) was sequentially extracted with petroleum ether (PE), ethyl acetate (EE), n-butanol (BE) and water (WE). The total content of phenolics and flavonoids was then measured by using spectrophotometry. Phenolic compounds in the extracts were profiled by using ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS), and differential metabolites were screened and quantified by using an untargeted metabolomics approach. Antioxidant activities in vitro were assessed through DPPH free radical scavenging, ABTS⁺ free radical scavenging and FRAP methods. Furthermore, the phenolic markers of antioxidant activity in the peels were explored through pearson correlation analysis. The results indicated obvious variations in the total phenolic and flavonoid content among the extracts (P<0.05), ranked in descending order as follows: EE>BE>CE>WE>PE. A total of 33 phenolic compounds were identified from both CE and each fractional extract, while CE, EE, and BE exhibited a greater variety and quantity of phenolic compounds. Principal component analysis (PCA) distinguished the metabolites of extracts, while orthogonal partial least squares discriminant analysis (OPLS-DA) identified p-hydroxybenzoic acid, protocatechuic acid, isoquercitrin and iso-orientin as differential compounds. EE exhibited the highest levels of p-hydroxybenzoic acid (653.44 μg/g), isoquercitrin (2420.64 μg/g) and iso-orientin (113.23 μg/g), while CE showed the highest content of proto-catechuic acid (152.40 μg/g). The in vitro antioxidant activity of passion fruit peel varied significantly among extracts, with EE showing the strongest capacity, suggesting its potential as a premium antioxidant agent. The correlation analysis revealed that the total phenols and flavonoids formed the basis of antioxidant active substances, while iso-orientin and isoquercitrin were the antioxidant active phenolic markers. The finding provided fundamental data for establishing quality control standards of antioxidant products derived from passion fruit peels, as well as for the precise development and utilization of phenolic compounds in the peels.